(1) Field of the Invention
The present invention relates to a double-wall aerosol container including of a jacket and an inner bag disposed inside the jacket such that the inner bag communicates with to a nozzle. An aerosol content, which is preferably separate from the propellant, is charged to the inner bag and is adapted to be sprayed without contacting the propellant by pressurizing the inner bag from the outside thereof.
(2) Description of Related Art
In a conventional technique for spraying an aerosol content, a deflatable inner bag is disposed in a jacket of an aerosol container, with a propellant being charged in the space between this inner bag and the jacket so as to prevent the aerosol content from contacting the propellant, and to allow the aerosol inner bag to be pressurized by the propellant to spray the content as an aerosol with the aid of this pressure.
In such a technique, as described in Japanese Utility Model Publication Nos. Hei 5-32221 and 6-32863, and in Japanese Unexamined Patent Publication No. Hei 2-218461, the inner bag is connected to the jacket by an annular engagement ridge formed to protrude inwardly from the inner peripheral surface of the jacket at an upper part of the jacket. The upper part of the inner bag is partly brought into contact with this engagement ridge, and the thus contacted part of the inner bag is pressed against the inner surface of the engagement ridge by the outer circumference of a housing, thus fixing the inner bag relative to the jacket.
That is to say, the fixing of the inner bag to the inside of the jacket according to the prior art, as described above, is achieved by nipping the upper end portion of the inner bag, which is as thick as the thin deflatable storage section between the housing and the jacket, so as to secure the inner bag to hang in the jacket with the aid of this nipping force.
Accordingly, when the inner bag is assembled in the jacket in the production process, it is difficult to engage and retain the inner bag within the jacket, and the inner bag must be retained in the jacket using a special tools and the like. With the inner bag being retained by the tool, the housing must be inserted through the opening of the jacket to allow the upper end portion of the inner bag to be nipped securely between the outer peripheral surface of the housing and the inner peripheral surface of the jacket. This requires additional effort in manufacturing. It is therefore disadvantageous with respect to workability to apply the housing after the inner bag is engaged with the inner peripheral surface of the jacket, as described above.
Under such circumstances, it is also known to secure the upper end portion of an inner bag to the outer peripheral surface of a housing and to attach the resulting housing to the jacket. However, in order to secure the upper end portion of the inner bag to the outer peripheral surface of the housing beforehand, an extra manufacturing step is required for securing the inner bag, and also the procedure of securing the inner bag in the pretreatment step therefore must be considered, requiring more complex manufacturing. In addition, when the inner bag integrated with the housing is inserted into the jacket, the soft inner bag is often inadvertently brought into contact with the rigid housing during that process, damaging the inner bag and disadvantageously requiring an increased number of procedures in the assembly operation.
Further, since the upper end portion of the thin inner bag is conventionally nipped securely between the outer peripheral surface of the housing and the inner peripheral surface of the jacket; even after completion of assembly, the inner bag often breaks at the nipped portion or slips out of position.